Cathodic delamination of polyurethane/multiwalled carbon nanotube composite coatings from steel substrates

Polyurethane composite coatings with different multiwalled carbon nanotube (MWCNT) contents were prepared on steel substrates to study the effect of MWCNT content on the cathodic delamination of the polyurethane composite coatings. The cathodic delamination of the polyurethane composite coatings was measured using a Scanning Kelvin Probe (SKP). An increase in MWCNT content to 0.5 wt% significantly reduced the cathodic delamination of the polyurethane composite coatings because the high density of MWCNTs blocked the transport pathways of water and oxygen molecules through the coating. It could be concluded that the incorporation of MWCNTs was a possible way to lessen the cathodic delamination of the polyurethane coatings. (C) 2016 Elsevier B.V. All rights reserved.